Buckwheat flour is well known for its highly antioxidative ingredient, rutin. We have undertaken to examine alterations in the characteristics of rutin treated with various proteins. In this study, the radical scavenging activities of a rutin-ovalbumin complex were examined. Dissolved rutin hydrate and ovalbumin were combined and boiled in water for 10 min. In the resulting rutin-ovalbumin complex, a new high molecular weight peak was detected using gel permeation chromatography analysis, and an existing high molecular weight area of ovalbumin was observed to be increased by the addition of rutin. This suggested that ovalbumin molecules produce a complex through their interaction with rutin. Alkaline luminol chemiluminescence and electron spin resonance analysis revealed the formation of a rutin-ovalbumin complex that markedly enhanced the peroxyl, but not the hydroxyl, radical scavenging activity of rutin. Rutin also demonstrated antioxidative activity against hydroxyl radicals in a DNA protection assay. We therefore conclude that, compared with ovalbumin or rutin alone, the rutin-ovalbumin complex has improved antioxidative activities in the form of enhanced peroxyl radical scavenging activity and DNA protection from apurinic/apyrimidinic site formation caused by hydroxyl radicals.

Germinated buckwheat is buckwheat seeds soaked in water just until it begins to bud. Buckwheat sprouts are seedling plants of buckwheat grown up to 10-15 cm. The purpose of this study was to determine the optimal growth period for accumulating the most abundant functional phenol(s) in germinated buckwheat that had been soaked in darkness and buckwheat sprouts cultivated by hydroponic culture. The rutin contained in germinated buckwheat was analyzed by CE (capillary electrophoresis). Phenols, including isoorientin, orientin, isovitexin, vitexin, and rutin were separated from buckwheat sprouts by HPLC and identified by LC-MS. The highest rutin content in germinated buckwheat was found to be 15.8 mg/100 g DW at 20 h after germination. Buckwheat sprouts contained five kinds of major phenols. The highest amounts of isoorientin, orientin, isovitexin, and vitexin were measured at day 3, with the exception of rutin, and then a gradual decrease was observed as the sprouts grew. The quantities of isoorientin, orientin, isovitexin, and vitexin at day 3 were 5.8, 11.7, 26.2, and 28.9 mg/100 g FW, respectively. The rutin content rapidly increased to 109.0 mg/100 g FW until day 6. The highest total phenols in buckwheat sprouts were 162.9 mg/100 g FW at day 6. Germinated buckwheat soaked for 20 h and buckwheat sprouts cultivated for 6 days were rich in dietary phenol(s), which makes these plants a valuable functional food for human consumption.

The content of the flavonoid rutin was determined in different milling fractions of buckwheat seeds and in buckwheat stems, leaves, and flowers. The extraction was performed by using a solvent containing 60% of ethanol and 5% of ammonia in water. The extracts were analyzed by capillary electrophoresis (running buffer of 50 mM borate (pH 9.3), 100 mM sodium dodecyl sulfate; determination at 380 nm). In bran fractions the concentration of rutin was 131-476 ppm, and in flour fractions 19-168 ppm. On average, about 300, 1000, and 46000 ppm of rutin were found in leaves, stems, and flowers, respectively. The results indicate that buckwheat could be an important nutritional source of flavonoids, especially in countries with a low mean daily flavonoid intake.

Buckwheat food is a good source of antioxidants, e.g. rutin, and other beneficial substances. Here we investigated the effects of the intake of common buckwheat (low rutin content) and tartary buckwheat cookies (high rutin content) on selected clinical markers. A double blind crossover study was performed among female day-care centre staffs (N = 62) from five day-care centres. Participants were randomly divided into two groups. The first group initially consumed four common buckwheat cookies per day (16.5 mg rutin equivalents/day) for two weeks, while the second group consumed four tartary buckwheat cookies per day (359.7 mg rutin equivalents/day). Then the groups switched their type of cookies and consumed them for another two weeks. We monitored selected clinical markers related to cardiovascular disease and lower airway inflammation, lung function, and subjective breathing difficulties in the staffs. Intake of tartary buckwheat cookies reduced the serum level of myeloperoxidase (MPO) by a factor 0.84 (p = 0.02). When grouping the two types of buckwheat cookies together, there was a reduction of total serum cholesterol (p < 0.001) and HDL-cholesterol (p < 0.001) during the study period, with improved lung vital capacity (p < 0.001). The degree of reduction in total and HDL cholesterol levels was similar in staffs with low and high body mass index (cut off 25). In conclusion, intake of tartary buckwheat cookies with high level of the antioxidant rutin may reduce levels of MPO, an indicator of inflammation. Moreover, intake of both types of buckwheat cookies may lower cholesterol levels.

为了探讨苦荞品种在云南昆明周围夏播的优质高产栽培的最佳播期，以3个品种（‘云荞1号’、‘迪苦一号’、‘晋苦6号’）为供试材料，研究了4个播期（6月25日、7月5日、7月15日、7月25日）对其生育期、农艺性状及产量性状的影响。结果表明，随着播期的迟延，3个苦荞品种的生育期均明显缩短，而株高、主茎节数、一级分枝数随着播期的迟延，没有规律性的减少或增加，而株粒数、千粒重、株粒重及产量都随着播期的推后均有降低的趋势。并且3个品种在产量上分别与早播（6月25日）比，7月5日减产69.4%~74.8%，7月15日减产61.4%~93.3%，7月25日减产88.3%~94.7%。在本试验条件下，云南夏播苦荞的优质与高产相结合的最佳播期是6月25日，使产量达到最高水平。

在吉林省农业科学院作物资源研究所育种试验地(公主岭)对春小麦品种吉春13号进行不同播期和密度试验。播期为3月29日、4月10日和21日,种植密度为350万、400万、450万、500万和550万株&#x000b7;hm^-2,研究不同处理组合对穗数、穗粒数、千粒重和产量的影响。结果表明,不同播期对穗数、千粒重和产量均有显著影响,不同密度对产量也有显著影响。春小麦吉春13号在4月10日播种、密度500万株&#x000b7;hm^-2下,籽粒产量最高,达5.953 t&#x000b7;hm^-2。

为阐明播期对不同类型机插稻产量及光合物质生产特性的影响,以三系籼粳交甬优2640(大穗型)及超级稻武运粳24(多穗型)为试验材料,依据江苏省里下河稻区稻麦周年生产实践,设置6个播期,采用毯苗机插方式,研究不同播期条件下机插稻产量及光合物质生产特性的影响。结果表明,各水稻产量随播期推迟显著下降,但变化幅度有差异;播期推迟,水稻生育时期相对延迟,生育期缩短,主要生育阶段积温及其利用率明显降低;产量构成因素中穗数和千粒重受播期的影响较小,每穗颖花数和结实率变化较大;随播期推迟,水稻主要生育阶段光合势下降,群体生长率和净同化率于生育前期上升,生育中、后期明显下降,叶面积指数、干物质积累在拔节期略有升高,在抽穗期和成熟期相对降低,抽穗后叶面积衰减率呈上升趋势,收获指数下降。试验设置播期范围内,抢时早播有利于调节机插稻主要生育阶段干物质积累,形成"前小、中高、后强"的高质量水稻群体,易攻取高产。从生育安全性考虑,机插稻最迟应在6月15日播种。迟播条件下,应尽量避免选用大穗型品种,规避种植风险,降低生产成本投入,因此大穗型品种最晚播期宜提前至6月5日。本研究可为机插稻高产、高效生产提供参考。